Improvement in speed-protractors for railroad time-table charts



2 SheetsSheet 1 A. Hm... S?EED-PROTRACTOR FOR RAILROAD TIME-TABLE CHARTSNo. 172,436. Patented J-gn.1 8,1876.

1 W flymfl N.PETERS, FHOTO-UTHOGRAFHER. WASHMGTON, D C.

2Sheets-Sheet2. A. HILL.

SPEED-PROTRACTOR FOR RAILROAD TIME-TABLE cmms. Nu. HZASG. Patented Jan.18, 18176.

lllll llllllllll[ll llll ll%lllll| llll|'lllill |r|| III IIH BNVENTBHALBERT HILL, OF BROOKLYN, NEW YORK.

IMPROVEMENT IN SPEED-PROTRACTORS FOR RAILROAD TIME-TABLE CHARTS.

Specification forming part of Letters Patent No. H72A36, dated January18, 1876; application filed December 4, 1875.

To all whom it may concern:

Be it known that I, ALBERT HILL, of Brooklyn, in the county of Kings andState of New York, have invented a new and use i'ul Improvement inSpeed-Protractor for Railroad Time-Table Charts, of which the followingis a specification:

Figure 1, Sheet 1., is a plan view of the in strument. Fig. 2, Sheet 1,is a detail section of the same, taken through the line w 00, Fig. 1.Fig. 3, Sheet 1, is a detail plan View of the lower head. Fig. 4, Sheet2, is a view illustrating the use of the instrument.

Similar letters of reference indicate corresponding parts.

The object of this invention is to furnish an improved instrument, bythe use of which the construction of railroad time-table charts will begreatly facilitated, inasmuch as the calculations of the speed of trainsbetween stations heretofore necessary will be done away with, theinstrument itself showing the speed at once.

The invention consists of an improved instrument, formed of the blade,the rigid head, and the pivoted head, having a speed-scale marked uponits upper surface, to adapt it to be used in constructing railroadtime-table charts 5 and in the pivoted head, provided with a speed-scaleupon its surface, in combination with the blade, whether the rigid headbe used or not, as hereinafter fully described.

A is the blade of the instrument, which is made of suitable length,breadth, and thick ness, and its lower end is firmly secured in a recessin the upper head B, so that the lower surfaces of said blade and headshall be flush. The upper head B is made like the head of an ordinaryT-square, except that the edge toward the blade is beveled down to theupper surface of the blade A, as shown in Fig.

2. G is the lower head, which is made a little longer and considerablywider than the upper head B. Through the lower head 0, near its center,passes a pivot, D, the head of which is let into the lower surface ofsaid head 0, and rests upon asoft washer, E. The pivot D also passesthrough a corresponding hole in the middle of the upper head B, thecenter of which hole is in the center line of the blade A. The neck ofthe pivot D is hollow and screw-threaded for the reception of theclamping-screw F, which screw F serves to fix the .upper head B in anydesired position upon the lower head G. Upon the upper surface of thelower head 0 is marked out the speedscale G, which, by means of thefigures at the end of each scale-line, indicates the number of miles perhour at which the train moves. The scale-lines are symmetricallyarranged upon both sides of the pivot D.

In using the instrument, set the beveled edge of the upper head B flushwith the first or base line of the scale Gr, upon the ends of whichthere is no figure. Then see that either edge, of the blade Acorrespondswith any hour-line, H, of the time-table chart. This being done, loosenthe upper head B sufficiently to admit of its motion upon the lower head0. Now move the instrument with either edge of the blade A upon thetime-line H, at which you wish to start your train. Then set the bevelededge of the head B flush with the line of the scale, G, indicating thespeed desired for your train. The intersection of the edge of the bladeA with the hourline H at the station to be reached will give the time ofarrival; or, vice versa, lay the edge of the blade A to correspond withthe time of departure and arrival at two stations, respectively, and theposition of the beveled edge of the upper head B upon the scale G of thelower head 0 will at once give the rate of speed necessary to make thedistance in the given time.

If desired, the upper head B may be omitted and an index-finger used topoint to the lines of the scale Gr.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. An improved instrument, formed of the blade A, therigid head B, and the pivoted head O, having a speed-scale, G, markedupon its upper surface, to adapt it to be used in constructing railroadtime-table charts, substantially as herein shown and described.

2. The pivoted head 0, provided with a speed-scale, G, upon its surface,in combination with the blade A, whether the head B be used or not,substantially as herein shown and described.

ALBERT HILL.

Witnesses:

JAMES T. GRAHAM, T. B. MOSHER.

